To reduce data storage and data transmission, most surveillance camera systems have motion detection capabilities for activation when motion is detected. Motion activation can be derived from a wide range of devices and methods such as video motion detection, infrared motion sensors, and a variety of video analytic metrics. They do boil down to some kind of sensitivity adjustments for the selected motion detection metric(s) to achieve the desired results. When detection is too sensitive, too much false motion detection will result. When it is not sensitive enough, important motion such as an intrusion may be missed.
The current common practice is to either ignore the sensitivity adjustment issue or set motion sensitivity to very high, as the costs of data storage and bandwidth are not prohibitively expensive. In recent years when live video monitoring has become more common, to reduce the monitoring load, some conscientious installers are beginning to pay attention to proper sensitivity adjustments.
To perform motion sensitivity adjustment (or motion calibration), a moving object, typically a human being moving around to resemble the motion of an intruder, is employed to simulate an intrusion.
Motion calibration is particularly challenging for outdoor cameras. A calibration done during daytime is unlikely to be valid at nighttime, particularly when motion detection is done through the video motion detection method, which is one of the most common forms of motion detection for camera systems. The views of the same camera in daytime and nighttime are very different. The reduced light level at night substantially lowers the contrast of any motion seen through a camera, thus requiring higher motion sensitivity adjustments for proper motion detection. Therefore, to achieve reliable video motion detection results, motion calibration should be done after dark. In winter when sunset occurs early in the evening, doing night calibration is not as challenging for the worker. However for the months when sunset occurs late in the evening, night calibration poses a major challenge on workers' schedules since they no longer enjoy the typical work hours like the majority of the work force. This challenge makes the calibration job less desirable or requires higher pay to compensate.
In addition, night calibration typically requires two people, one moves around to simulate the motion of an intruder and the other sets detection sensitivity. An alternative for only one worker is to walk back and forth to simulate movement, review equipment's motion detection performance, make adjustments, and repeat the process again as necessary. Both methods are labor intensive, not to mention raising possible safety issues when walking in the dark at night.
The subject invention is a calibration system including a method and apparatus for overcoming the aforementioned problems of labor inefficiency, possible safety hazards and irregular work hours associated with nighttime motion calibration. One of the most significant challenges is to utilize an apparatus which is low cost, easy to use and readily transportable, as quite a number of them may be needed for a particular job. Also, the time and cost involved in retrieving the calibration devices may counteract the economic benefits of the invention unless the devices are so inexpensive that they can be disposable.
In essence, the subject invention is a specialized very low cost motion generator with its motion and control suitable for video motion calibration, and having very high energy efficiency so that it can be powered by an inexpensive battery.
Alternative motion generators of various types are known generally in the robotics and sign industries; however, applicant is not aware of any system employing motion generators in the field of the present invention using the apparatus and method disclosed and claimed herein.
A patentability search directed to the present invention located the following patent documents: U.S. Pat. No. 7,636,039, issued Dec. 22, 2009, U.S. Pat. No. 5,363,688, issued Nov. 15, 1994, U.S. Patent Application Pub. No. US 2014/0088904, published Mar. 27, 2014, and Korean Patent No. KR101443151, granted Sep. 24, 2014.
The located prior art is not very relevant to the present invention.
With the existing robotics prior arts, one can certainly create a moving robot, which generates motion that may simulate human movements. However, it is so cost prohibitive that is not a real solution to the problems addressed by the present invention.
In the sign industry a variety of moving signs serve as motion generators and at costs much less than a moving robot.
The common moving signs include flags, streamers, balloons, and other inflatable objects. When there is wind, flags, streamers, and balloons will move, but their movements are often limited and unpredictable, not suitable for motion calibration. When there is no wind, they are motionless. Other inflated signs with air or helium behave just like large balloons. There are other inflatable promotional objects with a running air blower that can generate significant and predictable movements for motion calibration. However, the air blower consumes too much energy to be powered by a small battery, and is still too costly to be practical. With the advent of human moving board signs at street corners, electrical equivalents of moving human signs driven by a large motor to move a signboard are now available. Unfortunately, they also consume a lot of power and are expensive to build, therefore not practical for motion calibration.